Revolving furnace



L. P. BASSET.-

REVOLVING FURNACE.

APPLICATION FILED SEPT. 12, 1919.

9g Patented Mdr.22,1921.

Izwezzim v LBfla/saefi; 3y% M.

UNITED STATES LUCIEN PAUL BASSET, 0F PARIS, FRANCE.

REVOLVING FURNACE.

Specification of Letters Patent. Patented M .22 1921- Application filed September 12, 1919. Serial No. 323,378.

To all whom it may concern Be it known thatI, LUOIEN PAUL BASSET, of 92 Rue de la Victoire, Paris, France, engineer, have invented Revolving Furnaces, of which the following is a clear, .full, and exactdescription. t,

In a previous patent of the applicant,- a process for the direct production of iron and steel has been described, this process consisting in effecting the reduction of the ore and the melting of the metal in an extremely hot flame of carbon monoxid, obtained by the combustion of carbon or of a sprayed hydrocarbon in the proportion of air necessary for causing this combustion to practically produce only carbon monoxid.

'This invention has for its object an improvement for carrying out this process for the purpose of obtaining a continuous production and refining of the metal.

This improvement consists essentially in carrying out the said process in a revolving furnace of special construction. I

The said furnace essentially comprises:

(a) Arelatively long main cylindrical body, the longitudinal axis of which is slightly inclined. Y Y

(b) A reaction chamber arranged at the lower end of the main body and integral therewith, this chamber having a larger diameter than that of the main body, so as to constitute a pocket in which is collected the molten metal.

(c) A heating device for projecting into the reaction chamber a mixture of finely divided carbon (or of a hydrocarbon) and hot air, in the required proportions so as to practically produce only carbon monoxid.

The inventionis clearly illustrated in the accompanying drawings in which- Figure 1 is a longitudinal sectional view of one portion of the improved furnace, and,

Fig.- 2 is a longitudinal sectional View of the remaining portion thereof.

Referring now, more particularly to the accompanying drawings the furnace comprises a main cylindrical body a, which is relatively long and which is arranged at an inclination, while formed at the lower end of the furnace is a reaction chamber 6 having a larger diameter but of less length than the body a.

This chamber 6, as intimated is of a larger diameter'than the body a of the furnace and constitutes the front part of the latter a pocket in Whlch is collected the molten metal.

Mounted about the outer face of the body are a plurality of rolling collars 'c which revolve on rollers d journaled at theupper ends of suitable supports, while in addition there is mounted on the outer face a toothed wheel 6 which is adaptedto be engaged by gearing (not shown) so that rotary motion will be imparted to the furnace at the desired speed. I

This furnace a, b is internally provided with a refractory lining; in the hottest part of the furnace the composition of this lining is suited to the chemical operation which must be effected in the reaction chamber 7), and will be according to circumstances either acid, or basic or neutral.

At the frontv part of the chamber 6 is formed an orifice 7" through which enters a twyer g; through the latter are injected hot air and finely divided carbon; the carbon contained in a hopper h is regularly discharged by a screw conveyer 2' the speed of which is variable, so that the feeding of the carbon may be effected in the required proportion for causing the combustion of this carbon in the chamber 6 to practically produce only carbon monoxid.

The air injected by the twyer g is adapted to befpreviously heated in any suitable heat exchanger (not shown in the drawing), the working of which may be continuous'or discontinuous, and in which is adapted to be led a fraction of the combustible gases issuing from the furnace.

At the front part of the chamber 1) are provided tap holes j, is; the tap holes j are nearer the periphery of the chamber 6 and the tap holes is are nearer the axis of the latter. The tap holes j which serve for the casting of the metal are' closed during the operation of the furnace and are opened but periodically; on the contrary, the holes, 70 through which is effected the tapping of the slag always remain open. 7

At its other end the furnace'a opens in a brickwork chamber Z in which the combustible gases issuing from the furnace are entrapped. When issuing from this chamber red heat, the carbon continues to burn alone..

Z these gases are sent by a blower m to the points where they are to be used.

- The iron ore to be treated, mixed with fluxes and with the quantity of carbon just sufficient for the reduction of this ore, is discharged at the end of the furnace by a screw conveyer n.

The operation is as follows:

' The furnace is lighted by means of fagots introduced in the chamber 6. When the Wood burns, air is gently blown and the screw conveyer z' is put in motionythe carbon is projected through the twyer in the chamber 6 and burns when coming in contact with the flaming wood. The temperature of the furnace rises and when at cherry- Whenthe chamber 6 is brought to white heat, it is ascertained that the proportions of air and carbon are such as to produce only carbon monoxid. If such was not the case, these proportions would be modified so as to satisfy this requirement. Then, by means of, thescrew conveyer n, the iron ore is introduced in the furnace; this iron ore, preferably finely crushed, being mixed with fluxes and with the quantity of carbon necessary for effecting the reduction of the ore. I

The continuous rotation of the furnace brings this mixture toward the hot portions of the furnace; the reduction of the ore is effected, and the metal obtained, which on entering in the zone of the furnace where the temperature is maintained at about 1600 0., melts and separates from the slag. The molten metal and the slag collect in the pocket constituted by the chamber 1) and separate by reason of their difference in density. I

When the slag reaches a suflicient height in the chamber 1), it flows away through the tap holes is, every time the latter are presented, in the course of the rotary motion of the furnace. As soon as the metal begins to flow off through these holes, the operator is thus warned that the pocket constituted by the chamber is full of metal; the tapping of this metal is then effected through the orifice j or its refining is effected in the furnace itself.

In the latter case the tap holes is for the slag are closed and in the chamber 6 is introduced an oxidizing and basic slag, or the elements of this slag, that is to say silica,

' iron oxid and lime.

Under the action of this oxidizing slag, the carbon, silicon, manganese and phosphorus are eliminated from the metallic bath and pass, with the exception of carbon, in the slag. The metal contains as impurity only sulfur. It can be eliminated in the furnace by the addition in the chamber 3) of a highly basic reducing slag or in any other suitable furnace.

When this refining operation is terminated, the slag is removed from the furnace through the tap holes 70 and the metal is tapped through the orifices j. After tapping, the holes 7 are reclosed and the operation continues.

The refining of the metal may also be effected in-the following manner If to the ore to be reduced has been added a suitable quantity of lime for entirely desulfurizing the metal, the latter contains only small quantities of carbon, silicon, manganese and phosphorus. The metal is then cast on the hearth of a Siemens Martin furnace and is treated with an OXidiZing and basic slag which eliminates all extraneous bodies. The Siemens Martin furnace may be heated by a fraction of the rich gases issuing from the furnace.

The main advantages of this type of revolving furnace are as follows l. The metal, held in reserve in the reaction chamber 6, at a very high temperature, may be, if desired, refined in the furnace it self. by any suitable process or in another furnace, or it may be cast in large quantity.

2. The production of the metal is continuous.

The furnace is not subjected to any variation of temperature during its operation.

4. The refractory lining is not brought to a sensibly higher temperature than that of the molten metal and, consequently, remains in good condition during a very long, period.

5. The continuous mixing of the mass insures an easy and complete reduction of the ore.

6. The methodical heating of the mass to be treated reduces the quantity of fuel.

It is to be understood that the dimensions and the details of construction of the present type of revolvin furnace may be varied without departing bereby from the scope of this invention.

Claim:

A revolving furnace comprising an elongated cylindrical body revolubly mounted at an inclination, and a reaction chamber arranged at the lower end of the body and integral with and of a diameter larger than that of the main body so as to constitute a pocket for receiving molten metal.

The foregoing specification of my revolving furnace for the direct production of iron or steel or for the production of cast iron, signed by me this 12th day of August,

LUCIEN PAUL BASSET. 

